Typically, moving of heavy or bulky objects over short distances requires the objects to be lifted or dragged to the desired position. This often necessitates the involvement of two or more people. An example of an object that frequently requires movement over short distances and that is too bulky for one person to move and difficult to drag is a picnic table. Previously, others have attempted to attach wheels in various ways to facilitate the movement of objects.
Permanently attached wheels have been described for picnic tables and boats. U.S. Pat. No. 4,974,284 (Campbell) describes a wheel assembly consisting of wheels attached to the opposite legs of a picnic table. The wheels operate independently of each other and are not retractable. U.S. Pat. No. 2,848,229 (Miller) discloses a combination sand box and table. The table is equipped with a pair of wheels fixed to two legs. Again, the wheels are not retractable. U.S. Pat. No. 5,586,803 (Overpeck) discloses a movable picnic table having a pair of wheels mounted to a pair of legs. Foot brackets are attached to the other pair of legs to match the height increase due to the wheels on one pair of legs. The wheels are permanently attached to the legs and are not retractable. U.S. Pat. No. 3,514,154 (Kotler) discloses a folding picnic table having wheels attached to two legs. While the picnic table itself can be folded, the wheels are not retractable.
Foldable assemblies have also been described previously. Such assemblies generally require the insertion or removal of some parts for folding the assembly. U.S. Pat. No. 4,706,983 (Griswold) discloses a retractable wheel assembly used in towing a boat. A leaf spring support pivots about a pin. Another pin, which is removable, secures the leaf spring support to a channel. In order for the assembly to be retracted, the pin has to be manually removed. The pin is inserted back to lock the leaf spring in place for moving the boat. U.S. Pat. No. 4,615,534 (Blain) discloses a movable, foldable wheel support for boats. The foldable wheel support has a pin fitting on to two notches to hold the support in an extended position. The invention employs a closed loop system for raising and lowering of the wheel assembly. The support is folded by pulling upwards a rope loop secured to the support. The support is held in the folded position by securing the rope loop to a swivel attached to the boat. U.S. Pat. No. 3,616,474 (Lindblad), U.S. Pat. No. 3,831,211 (Bustamante), and U.S. Pat. No. 4,040,658 (Mayol) disclose retractable wheel assemblies in which positioning of the wheel in an extended or retracted position is achieved by inserting a removable pin.
Still others have disclosed devices that can be attached at the time of need. U.S. Pat. No. 4,076,305 (Sullivan) discloses a knock-down mobile picnic table and bench assembly having a wheel assembly that is not retractable. The wheels are kept separately and added to the assembly only after it has been stacked for transport.
Thus, while several wheel assemblies are known in the literature, most of the assemblies are either not retractable or require manipulation of parts for retraction. Therefore a need exists for an apparatus for moving objects like picnic tables over short distances, that is simple and easy to use.